restore: call post-restore scripts before network-unlock

post-restore script can fail, so it can't be called after network-unlock.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>